Whats mine is your, whats yours is mine
by Sonnie Celanna
Summary: It had been a few weeks since Izuku and Momo had learnt each others little ey had quickly become close friends in that time, Today was just going to be a new kind of training excerise, there should've been nothing to worry about. It was simple. But as Midoriya stared into the mirror and Momo's reflection stared back, he snorted annoyed. Nothing was ever 'simple' at U.A.


Midoriya beamed at the sight before him. Momo had a massive dorky grin on her face as she watched the two muscular men on her laptop screen trade blow after blow. She didn't realize but she always jolted her body to one side or the other as if she was an active participant in the fight and it was one of the cutest things Midoriya had seen in his life.

Ever since he had found out about her secret and shared his, the two had started partaking in the others hobbies. Midoriya absolutely loved seeing how people from the time before quirks thought powers would work and Momo, though she was reluctant at first, had started getting into the skating lessons. Her excitement when she'd finally landed an ollie for the first time had been akin to a child waking up on their birthday. Though it had been kind of embarrassing for both of them when she lost her usual composure and practically leapt into his arms in a hug.

The two teens were cuddled up together on the tall girls bed. It had been embarrassing for both parties the first time but it made it much easier to see the screen. (And though neither party quite had the confidence to admit it, they both loved the warmth of the other, it was comforting.)

The girl put her hands together similar to how one of the characters on the show had started to. Midoriya couldn't help his slight eye roll but he joined her in chanting the attack name as had become tradition whenever they saw this move in action.

"Ha me, ha me, ka!" the two were quiet about it not to attract attention but still had intensity in their voices as if they were the ones doing the move. The greenette could hear Mina calling them a bunch of dorks, even though she wasn't even aware of the new tradition for Momo and Midoriya. For the greenette it felt like watching a hero battle and chanting the names of the ultimate moves with the pro's.

The two laughed a little at their antics as the fight came to a standstill and after a dramatic narration the credits rolled. While they didn't start the next episode as Midoriya had to leave soon, neither did they rush to get up.

The black haired girl nuzzled into the boys chest slightly as he kept one arm wrapped around her. It was a nice, quiet moment the two usually shared at the end of their anime mini-marathons, simply enjoying being with such a close friend

Momo simply thought about how grateful she was to have Midoriya as a friend with his kind personality and adorable demeanor while said boy's thoughts drifted to earlier that day in class.

"Alright listen up. This is our guest instructor Quickswitch." Mister Aizawa said, bored eyes scanning the room. they were in one of the many gyms the school had available. "He's here for a special kind of training exercise. I'll let him explain the details."

The man walked forward, his hero outfit relatively plain. It was nothing more than a simple spandex bodysuit that was all red on the left side and all white on the right. Midoriya left a mental reminder in his head to research the hero when he got back to the dorms as he didn't recognize him despite his extensive research on pro heroes.

"Hello class 1-A. As I understand it, you're the most troublesome class in this school so I can't wait to get started and see if this class goes the same route." The man joked with a grin. Despite his words his green eyes held a gentle kindness and playfulness. "When you're a pro, you have to be prepared for any eventuality. And I do mean ANY eventuality. I'm sure the incident with the USJ was a pretty big indicator of this lesson."

A noise of affirmation arose from some of the students while others merely shuddered. The USJ was not something any of them liked to be reminded of.

"Now, does anyone want to take a guess what my quirk is? I'll qt least give you this much to work with, its an emitter type." The mysterious pro smiled like a kind grandfather, and much like how Midoriya's own grandfather had been in the few years he knew him, there was also a familiar mischievous spark in the pro's eyes. All eyes seemed to snap to the greenette before he even began talking as if the class were aware he'd take a stab at the question.

"Sir, your hero name is likely also a hint towards your quirk due to the fact the name is similar to a quirk name in of itself. Considering the design on your costume as well, I would guess your quirk involves swapping 2…things, though i'm not sure what. It could be the placement of two objects, personalities, quirks, bodies. All of those could relate to this lesson about the unexpected you will be delivering and-" The boy slowly descended into his usual muttering habits, much to everyone's amusement or chagrin.

"Midoriya, you're doing it again. Stop it." Aizawa spoke up with a half-hearted glare that only really served to make their teacher look more tired.

"Sorry, mister Aizawa sir!" The boy apologized as some of the class sniggered.

"W-well…clearly you've got some pretty bright young minds here. Midoriya was it? Well done, as you guessed my quirk allows ne to swap people's bodies and by proxy, their quirks" Quickswitch explained and immediately the entire class became more alert (if it were even possible) as their excitement and curiosity came through.. "There are some quirks that only switch people's quirks however naturally there are also quirks that have preventive measures against such powers. Still that's only some, eventually you may run into a fiend swapping quirks and have yours changed in the mix. It is a requirement for a hero to be able to adapt to their circumstances quickly and proficiently. There has been some concern in the past over these kinds of lessons when it was done with Instructors who could only swap quirks. Some need the right body to be effective or are incredibly dangerous when used by those not supported to wield the powers which is why UA saw fit to start making me teach this class as a special guest."

"This will be a three hour long exercise, where you will all have your bodies and quirks swapped. It will be standard sparring, Quickswitch will help ease any discomfort." Aizawa explained before turning to the body swapping hero while pointing at the short teen that was Mineta. "I already have reservations about switching a bunch of teenagers into bodies of the opposite sex however I am setting most aside for the sake of their training however this particular student is not to be swapped with any girls at all."

Mineta let out an audible whine that was frankly just pitiful.

The training itself was nothing particularly impressive, not that it was to surprising. A majority of the students became pretty clumsy in one another's bodies, Kaminari (within Ashido's body) had attempted her usual acid skating stunts and almost collided with the wall, unable to stop sliding.

Koda (controlling Asui's body) had launched himself into the air via the frog tongue and smacked his (her?) head

Iida had sneezed while in Todoroki's body and accidentally created a massive ice barrier while simultaneously exploding into flames.

Midoriya had initially been concerned about his body and his classmates using his power. While he was certain someone like Todoroki or Yaoyorozu would hold back and learn his full cowling rather quickly, there was no guarantee it would be them who got his body.

His main concerns were 1) Kaminari, seeing as the electricity teen would commonly fire at 100% without a second thought despite the effects to his brain if he wanted a clean win. In Midoriya's body, that was just asking to be hospitalized.

And more importantly 2) Kacchan. While he was sure if they were told to swap the explosive blonde would initially refuse, Aizawa would probably threaten expulsion an force the swap. Of course, Midoriya wasn't worried about Kaccan not having good enough control to use fowl cowling, he actually expected the blonde to learn easier than anyone else.

What Midoriya was worried about was a 'Bitchy Blonde Bakugou hissy fit' as his middle school classmates used to call them. (He may have had the bullying the worst but the bullying wasn't isolated to one lone target, they were just more subtle about how they insulted someone as volatile as Katsuki Bakugou. Aldera Middle School sucked.)

Wherever Midoriya was involved, Bakugou's outburst got worse and when he started to throw tantrums as he still did even now, even if they were less frequent, he started to get some delusional ideas. He was sure the blonde would become convinced he was somehow better than Midoriya even in the greenette's body and try to use 100%, just to be proven wrong.

As it turned out though, Midoriya's fears were all for naught. He had been swapped into Sero's body first and during their sparring match The original tape wielder had been able to summon One for All at all, even after being given pointers by Midoriya himself. For his part, Midoriya had took to the tape quirk with a grace that not many others were managing with other quirks.

They all realized what had happened when Midoriya, in Sero's body, copied his usual summoning of One for All to help with summoning the power. Much to everyone's surprise familiar green lighting had started to surround Midoriya despite being in a different body.

Even Aizawa hadn't managed to contain his shout of surprise. Quickswitch walked forward, looking surprised but not as much as everyone else. "Well this is rare. It's not the first time this has happened but it's a very uncommon occurrence. Midoriya, if I may, would you please allow me to switch you into another few bodies to see what's causing this?"

"Yes i'd like to know as well." Aizawa said evenly, looking at Midoriya with calculating eyes. Midoriya agreed and had been made to swap with a few other students.

Satou, Ojiro, Hagakure, Jirou and even Aizawa at the end (seeing his original body with Aizawa's scowl was a really surreal experience. Of course everyone else probably thought that about seeing their teacher with Midoriya's nervous smile.) It was the same every time, Midoriya retained One for All on top of the bodies original quirk while whoever he was swapped with had to work with a completely quirkless body. Bakugou seemed weirdly pleased with the turn from inside Tokoyami's body, while everyone else cursed Midoriya's luck and started to fear for their bodies safety.

Quickswitch adapted to the situation fast, beaming brightly. "Well this is unexpected but its not something we can't work with. To explain for you all, it's theorized that some quirks are proof of souls, that certain quirks bond to the users soul. If this were to happen, then a quirk like mine would be unable to properly change the quirk of the user and it would seem your classmate here is proof of this. We can still work with this of course, because mister Midoriya's quirk travels with his 'souls' as it were, his initial body will be left quirkless. While i'm sure most of you have already had some kind of experience with this from your teachers quirk, this will be good opportunity to get used to not relying solely on powers."

The pleased look on Bakugou-Tokoyami's face dissipated instantly at that. Everyone just accepted it as an unexpected addition to the lesson for them and tried their best not to think about how horribly destroyed their bodies could become with Midoriya's quirk.

The rest of the class went without a hitch, Midoriya managed to not wreck anyone's bodies as he knew the limits of his quirk (and did his best to hide the improvements it caused to the quirks it came in contact with.) As it turned out the boy could adapt naturally to almost everyone's quirks without much hassle thanks to his extensive note taking allowing him to understand the quirks.

Finally the class began to reach its tail end, as most people were swapped back into their own bodies. Kacchan had immediately started exploding stuff happily when he got his power back, however the smoke it produced got thick quick and traveled to the guest teacher, who started coughing violently.

"BAKUGOU! ENOUGH!" Aizawa shouted out, erasing the blondes quirk as Momo and Midoriya rushed to their instructors side, holding him up. He managed to reign in his coughs as Kacchan and their homeroom teacher argued about what just happened.

"Aizawa, I think we'll need to call it here. It's not entirely your students fault, my quirk has a drawback with smoke, makes me a lot more susceptible to it and it messes with my power." Quickswitch explained and Midoriya swore that past the mild annoyance upon the pro's features, the mischievous glint had returned as well, masked by the irritated expression.

Midoriya shook his head, he was sure he was over thinking things, he had a habit of doing that. Still something about the moment had stuck in his brain. He was brought out of his thoughts at the light whine that arose from his friend.

"You should get back to your room Izuku." Momo said, however a sad frown clearly was upon her face as she said so, voice clearly not enthusiastic with seeing him go. "Mister Aizawa won't be easy on you if he thinks you're not getting enough sleep."

"Yeah, he's a hypocrite like that." Midoriya remarked with a light grin and the creation quirk wielder let out an overly dramatic gasp.

"Izuku Midoriya, did you just criticize our teacher?" Her tone would have seemed chastising to an outside observer, however the smile on her face spoke to the opposite.

"Maybe~" He smirked as he nuzzled into her side slightly, blushing before he got up and going to leave, but before he turned with a slight mischievous smile. "I'll see you tomorrow, Chi-Chi."

He narrowly avoided the pillow thrown at him for calling the girl her least favorite character. "i'm so getting you back for that in hero training!"

As Midoriya walked away he shook his head trying to avoid going back to the hero class in his mind. The only thing he should be worried about is if Asui just heard Momo's shout and was going to see him leaving.

Why was it whenever he ignored his gut feeling, it would come back to bite him and why hadn't he learned yet not to ignore it?!

He had had a rough awakening. As soon as his body returned to consciousness, he knew something wasn't right. The bed below him was comfortable, too comfortable. Not that his own bed wasn't too uncomfortable, however it was nothing like the one beneath him.

On his own bed he could always tell he was close to rolling off the edges due to it being a relatively small single bed he'd had for years. He couldn't sense the sides of this one though, he slowly raised his head to look around and paled immediately.

He recognized this room, even though it wasn't his. The fancy decorations, the low amount of space to actually walk around due to the oversized bed and the fragrance of perfume.

He was in Momo's room, in her bed. Immediately his brain started rushing a hundred miles a minute. Had he fallen asleep her last night by accident? No that couldn't be right, Momo would of woke him up and he remembered walking home. Did he somehow sleep walk back without the girl knowing? Seemed unlikely.

As he tried to come up with an answer he rolled over, seeing there was no Momo beside him and that's when he felt it. His legs felt too long, and there was a weight on his chest.

'No!'

Eyes widened in surprise as he threw the cover off of himself and looked down. Instead of his sleeping clothes, he had a long, white, familiar gown on and his view to his feet was blacked by two protrusions in his chest.

'Nonononono!'

He rushed over to where he knew a mirror was kept in the room and looked into it. Momo's beautiful black eyes stared back, her face contorted into the frightened expressions Midoriya knew he was making.

"No…"

Her voice said his words and then the previous days lesson flashed through his mind once more.

_"Smoke affects my power."_

He couldn't help it.

He screamed


End file.
